magnetic moment

A room of funhouse mirrors: you stand in the center, and the echo of your voice comes back from an unexpected direction, amplified and distorted. That is how spin waves in a thin magnetic film, excited by an antenna, reflect off defects and irregularities, creating a tangled pattern of fields.

An interpreter gets distracted by every rustle in the hall, and a one-hour meeting stretches into two. The same happens with a capacitive gyroscope: to hear the nanometer-scale displacement of its proof mass, it needs perfectly tuned gaps between the plates. The smaller the sensor, the harder it is to maintain that precision.

In 2015, the LIGO detectors caught the first ripple of spacetime from a black hole merger. Since then, hundreds of such events have piled up, each carrying the imprint of its ancestry: whether the holes were born together from a single pair of stars or met by chance in a dense cluster. The difference shows in the direction of their spin axes.

Two stars circle each other, gradually drawing closer. Their dance loses energy, and that energy escapes into space — in the form of gravitational waves, and sometimes other fields.

A spiral staircase sets the rhythm of footsteps: if a stream of people runs up it, their motion inevitably twists. Something similar happens in helical molecules — for example, in DNA or certain proteins. When an electric current is passed through such a molecule, electrons don't just fly straight.

A translator works in two worlds at once: to an outside observer, they are silent and unobtrusive, but inside their mind, a flurry of activity unfolds along clear lines of meaning. Altermagnets, a recently discovered class of magnetic materials, are much the same.

Gravity is the curvature of spacetime, not just an attraction, as Einstein showed. On such a curved "dance floor", even the hypothetical carriers of gravity — gravitons — move oddly.

Light bends around massive bodies: this has been known since Einstein's time. But what if gravity itself is not a smooth fabric of space but a stream of tiny carrier particles? Then a beam passing near a particle should not just bend but enter into a special quantum relationship with it. This relationship is called entanglement.

In the cold heart of a pure crystal, electrons flow like a viscous fluid — an idea predicted by Lev Landau. But the vortices of this fluid remained invisible, like a painting inferred from the noise of a crowd. Now scientists have created a nanostring: a semiconductor tuning fork with a circular cavity.

Two metal plates in a perfect vacuum attract each other. Even Richard Feynman compared emptiness to a boiling foam: particle pairs are born and immediately vanish, creating the Casimir effect. If the plates are asymmetric, they also start to twist — that's a vacuum motor. But rotation doesn't require oddly shaped parts.

We’re used to time flowing only forward. But quantum laws let it become like a coin showing heads and tails at once. Take a particle with its own spin — its intrinsic rotation. In a magnetic field, it spins like a top. Send this particle through a device where two opposing magnetic flows fight each other — and it will start moving into the future and the past at the same time.